Patterns of Drinking/Associated Lifestyle Factors

Critique 028. Changes over time in relation of social class to mortality from cirrhosis.

9 January 2011

Reference: Crombie IK, Precious E. Changes in the social class gradient of cirrhosis mortality in England and Wales across the 20th century. Alcohol and Alcoholism 2011;46:80–82.

To explore the nature of the social class gradient of cirrhosis mortality in England and Wales across the 20th century, data on male cirrhosis mortality by social class were obtained from the Registrar General’s Decennial Supplements for the years 1921–1991. This paper describes a dramatic change during the 20th century in the association between social class and mortality from liver cirrhosis. While deaths from cirrhosis were more common among higher social classes in the early part of the century, the pattern changed so that deaths from cirrhosis were much more common among the lower social classes by the end of the century.

Suggested reasons for the lower current rates among subjects at higher social class include different patterns of alcohol consumption, with regular moderate consumption (especially of wine with meals) becoming more common with higher social class subjects while binge drinking (especially of beer and spirits) remaining more common in lower social classes. However, a number of other factors may relate to the class differences in rates of hepatic cirrhosis, including a less healthy diet and greater rates of obesity (associated with hepatic fatty liver and cirrhosis) among lower social class subjects and social class differences in hepatitis rates. Further, certain medications, coffee consumption, and many other lifestyle factors are associated with hepatic cirrhosis. The actual reasons for the changes over time reported in this paper remain unclear.

Critique025.Pattern of drinking and type of beverage affect the relation of alcohol intake to coronary heart disease. 1 December 2010

Using cohort data from Belfast and France, investigators related weekly alcohol consumption, incidence of binge drinking (alcohol >50 g on at least one day a week), incidence of regular drinking (at least one day a week, and alcohol <50 g if on only one occasion), volume of alcohol intake, frequency of consumption, and types of beverage consumed to risk of coronary heart disease (CHD) events over a 10 year follow-up period. Overall, 60.5% of subjects from N. Ireland and 90.6% of French reported drinking alcohol at least once a week. Among drinkers, 12% of men in Belfast drank alcohol every day compared with 75% of men in France. Mean alcohol consumption was 22.1 g/ day in Belfast and 32.8 g/day in France. Binge drinkers comprised 9.4% and 0.5% of the Belfast and France samples, respectively.

Results showed that, after multivariate adjustment, the hazard ratio for hard coronary events compared with regular drinkers was 1.97 (95% CI 1.21 – 3.22) for binge drinkers, 2.03 (95% CI 1.41 – 2.94) for never drinkers, and 1.57 (95% CI 1.11 – 2.21) for former drinkers. The hazard ratio for hard coronary events in Belfast compared with in France was 1.76 (95% CI 1.37 to 2.67) before adjustment, and 1.09 (95% CI 0.79 to 1.50) after adjustment for alcohol patterns and wine drinking. Only wine drinking was associated with a lower risk of hard coronary events, irrespective of the country.

The authors conclude that regular and moderate alcohol intake throughout the week, the typical pattern in middle-aged men in France, is associated with a low risk of ischemic heart disease, whereas the binge drinking pattern more prevalent in Belfast confers a higher risk. While a strong inverse association between moderate alcohol consumption and cardiovascular disease has been demonstrated for decades, more recent research has emphasized the importance of the pattern of drinking (regular moderate versus episodic or binge drinking). Further, there continues to be debate about the potential greater effect of wine versus other beverages containing alcohol. This study shows that regular moderate drinking (especially of wine) is associated with lower risk of MI, but episodic or binge drinking (especially of beer or whiskey) increases the risk. Lifetime abstinence has a similar adverse relation to CHD as does episodic or binge drinking.

Critique 022. Alcohol consumption decreases with the development of disease.

In a cross-sectional study from the 2004 and 2007 Australian National Drug Strategy Household (NDSH) surveys, respondents were questioned about their current and past drinking, the presence of formal diagnosis for specific diseases (heart disease, type 2 diabetes, hypertension, cancer, anxiety, depression) and self-perceived general health status. The sample sizes for the 2004 and 2007 NDSH surveys were 24,109 and 23,356, respectively.

The authors report that respondents with a diagnosis of diabetes, hypertension, or anxiety were more likely to have reduced or stopped alcohol consumption in the past 12 months. The likelihood of having reduced or ceased alcohol consumption in the past 12 months increased as perceived general health status declined from excellent to poor (although the authors do not point out that lifetime abstainers were more likely than moderate drinkers to report less than excellent health status).

The authors conclude that the experience of ill health is associated with subsequent reduction or cessation of alcohol consumption (“sick quitters), which is consistent with most prospective epidemiologic studies. The authors also conclude that this may at least partly underlie the observed ‘J-shaped’ function relating alcohol consumption to premature mortality. On the other hand, most modern epidemiologic studies are careful not to include “sick quitters” within the non-drinking category, and relate health effects of drinkers with those of lifetime abstainers. Further, prospective studies in which alcohol intake is assessed at different times (rather than having “changes” based only on recall at one point in time, as was done in this study) usually indicate that subjects who decrease their intake are more likely to subsequently develop adverse health outcomes, especially related to cardiovascular disease, than those who continue moderate drinking.

Critique 017.Moderate alcohol intake is associated with a lower risk of total mortality than are either abstinence or heavy drinking. 5 September 2010

In a study based on data from 1,824 predominantly Caucasian Americans from the Western part of the United States, alcohol consumption at baseline was related to mortality risk during a 20-year follow-up period. Subjects were recruited into a longitudinal project that has examined late-life patterns of alcohol consumption and drinking problems. Lifetime abstainers were not included in the study, which focused on stress and coping processes among problem drinkers and non-problem drinkers. The sample at baseline included only subjects aged 55 to 65 years who had had outpatient contact with a health care facility in the previous 3 years.

The database at baseline included information on daily alcohol consumption, sociodemographic factors, former problem drinking status, health factors, and social-behavioral factors. Subjects who were not lifetime abstainers but did not report drinking at the time of the baseline examination were classified as “abstainers.” Data on potential changes in alcohol consumption during the course of the study were not collected. Death during follow up was confirmed primarily by death certificate.

The key results of the paper are that even when adjusting for sociodemographic factors, former problem drinking status, health factors, and social-behavioral factors, moderate drinking was associated with considerably lower risk of all-cause mortality. In comparison with “moderate drinkers” (subjects reporting up to 3 drinks/day), abstainers had 51% higher mortality risk and heavy drinkers had 45% higher risk. The study supports most previous scientific studies showing that moderate drinking, in comparison with both abstinence and heavy drinking, is associated with lower risk of total mortality.

Critique 007. People may change to a “healthier” pattern of drinking as they age.

In a prospective longitudinal study of a cohort of Americans in the “Baby Boomer” generation, subjects’ drinking habits were assessed at two points, when they were approximately 53 years of age and again when they were approximately 64 years of age. As the subjects got older, they began to consume fewer drinks per occasion but to consume alcohol more frequently; the net effect was little change in total alcohol intake for women but a slight increase for men.

In most epidemiologic studies, regular moderate drinking is the pattern associated with lower risk of many chronic diseases; hence, the described change in drinking pattern in this study (smaller amounts on more frequent occasions) can be considered a “healthy” change. Most long-term observational studies show a decrease in total alcohol intake with ageing, although reasons for such are poorly understood.

This paper emphasizes the importance of knowing the pattern of drinking, and not just the total number of drinks consumed over a week, when evaluating the impact of alcohol consumption on health and disease.

An analysis based on a very large number of subjects in France demonstrates, as have most other studies, that moderate consumers of alcohol have many associated healthy lifestyle habits: lower levels of body mass index, blood glucose, heart rate, stress and depression scores; higher subjective health status, HDL-cholesterol values, levels of physical activity and social status. The authors suggest that alcohol is not related causally to any of these factors, and that the other lifestyle factors, not alcohol consumption, are the reason that moderate drinkers have less cardiovascular disease. They chose a very narrow group of citations from the literature to support this contention.

The authors ignore a large number of well-conducted prospective epidemiologic studies showing that moderate drinkers are at lower risk over time of developing certain risk factors. Further, the authors of this paper ignore an immense basic science literature that suggests that alcohol is an important factor in the development of biological risk factors, atherosclerosis, and cardiovascular disease. Further, they do not describe a number of studies that have shown specifically that moderate drinking is associated with less cardiovascular disease and diabetes among subjects who are otherwise very healthy (non-smokers, not obese, physically active, and on a healthy diet).

There is no doubt that confounding by associated lifestyle factors can play a role in the lower risk of chronic diseases among moderate drinkers, who tend to also have other healthy behaviors. However, there is now a large body of scientific evidence that indicates that alcohol is an important factor in the lower rates of such diseases; current scientific data do not support the conclusions of the authors of this paper.

Critique 003.Moderate alcohol consumption markedly reduces the risk of diabetes mellitus, even among subjects with otherwise very healthy lifestyles.17 May 2010

In a very well-done analysis from a large Dutch population, it was shown that moderate drinking considerably lowers the risk of developing type 2 diabetes even among subjects who are otherwise following a healthy lifestyle (not obese, non-smokers, physically active, eating a healthy diet). Thus, it indicates that the effect of moderate drinking on lowering the risk of diabetes cannot be explained by other healthy lifestyle habits of such drinkers. Moderate drinking should be considered as a complement, and not as an alternative, to other healthy lifestyle habits that lower the risk of chronic diseases such as diabetes and coronary heart disease.